Electrode cover and evaporation device

ABSTRACT

The present invention provides an evaporation device for which maintenance is readily conducted, and further, provides an electrode cover which can prevent an evaporation material from being adhered to electrodes. Moreover, the present invention provides an evaporation device including an evaporation chamber; a holding portion for holding an object to be treated; an evaporation source; an electrode; an electrode cover; and a power supply, in which the evaporation chamber includes the holding portion in an upper portion, and includes the evaporation source, the electrode, and the electrode cover in a lower portion; the electrode cover covers at least a part of an exposed surface of the electrode; the electrode and the power supply are electrically connected.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to thin film formation devices.Specifically, the present invention relates to evaporation deviceshaving a mechanism which can form a film using a material by anevaporation method. The material is a material which can be formed as afilm by an evaporation method.

2. Description of the Related Art

In recent years, thin and flat display devices have been needed asdisplay devices in televisions, cellular phones, digital cameras, andthe like, and as the display devices satisfying this need, displaydevices using self-light emitting elements have attracted attention. Oneof the self-light emitting elements is a light emitting elementutilizing electroluminescence (EL), and this light emitting elementincludes a light emitting material interposed between a pair ofelectrodes and can provide light emission from the light emittingmaterial by voltage application.

Such self-light emitting elements have advantages over liquid crystaldisplay elements, such as high visibility of the pixels and no need ofbacklight and are considered suitable as flat panel display elements.Another major advantage of such light emitting elements is that they canbe manufactured to be thin and lightweight. In addition, extremely highresponse speed is also one of the features.

Further, such a self-light emitting element can be formed into a filmshape; therefore, surface light emission can be easily obtained byformation of a large-area element. Since this feature is hard to obtainfrom a point light source typified by an incandescent light bulb or anLED, or a linear light source typified by a fluorescent lamp, theself-light emitting element has high utility as an area light sourcewhich is applicable to a lighting system or the like.

Light emitting elements utilizing electroluminescence are classifiedaccording to the type of a light emitting material, that is, an organiccompound or an inorganic compound. In general, the former is referred toas an organic EL element, the latter as an inorganic EL element.

Light-emitting materials which are used for organic EL elements using anorganic compound are classified into high molecular compounds (polymer)and low molecular compounds (monomer). Such high molecular compoundmaterials are formed as a film by a wet method such as a spin coatingmethod or an inkjet method, while such low molecular compound materialsare formed mainly by an evaporation method.

In general, evaporation devices have a holding portion for holding asubstrate and an evaporation source holder for holding an evaporationmaterial. In an evaporation device using a resistance heating method, anevaporation source holder is placed between electrodes, and a current ismade to flow in a boat, a crucible, a filament or the like in which anevaporation material is held, with use of the electrodes, to heat theevaporation material, thereby forming a film.

However, such electrodes are positioned near a boat, a crucible, and afilament or the like, in which an evaporation material is held, andthus, there is a problem in that an evaporation material is adhered tothe electrodes at the time of evaporation. Therefore, when anothermaterial is evaporated, maintenance is needed to prevent contamination,in which the electrodes are cleaned to remove the material adhered tothe electrodes.

In addition, a large evaporation device has large electrodes and largeweight. In addition, in case of an evaporation device having a pluralityof evaporation source holders, since it has a plurality of pairs ofelectrodes, a large amount of labor is needed for washing theelectrodes. Such electrodes are needed to be fixed on a plate on whichan evaporation source holder is set; and such electrodes are preferablyfixed thereon from beneath such a plate so that the fixed portion isprevented from being contaminated. However, when the electrodes arefixed with a screw from beneath the plate on which an evaporation sourceholder is set, is also needed to be removed together with the electrodesto remove the electrodes for cleaning. The plate for fixing weighs 20 to30 kg in some cases, and thus, it is hard work to remove materialsattacked to the electrodes. When an evaporation device having aplurality of evaporation sources is used, a plate having a plurality ofevaporation source holders weighs more and the work operation is harder.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide anevaporation device for which maintenance is readily conducted. Inaddition, it is another object of the present invention to provide anelectrode cover which can prevent an evaporation material from beingadhered to an electrode.

An aspect of the present invention is an electrode cover which covers atleast a part of an exposed surface of an electrode. In particular, theelectrode cover preferably covers a face of the electrode, the facefronting the evaporation source.

More preferably, the electrode cover covers the whole exposed surface ofthe electrode. Note that a connection portion of each part of theelectrode or a portion for connecting the electrode and a power supplyis not needed to be covered.

In other words, another aspect of the present invention is an electrodecover which covers at least a part of an exposed surface of an electrodeholding an evaporation source.

Another aspect of the present invention is an electrode cover whichcovers at least a face fronting the evaporation source of an exposedsurface of an electrode holding the evaporation source.

In the above structures, the electrode cover is preferably formed usinga material having a high heat-resistance. Further, when an electrode isconstituted by plural parts and an electrode cover is provided betweenthe parts, the electrode cover preferably comprises a conductivematerial. Alternatively, when an electrode cover is not provided betweenparts of the electrode, the electrode cover may comprise a materialhaving a higher temperature limit of heat-resistance than a temperatureat the time of evaporation (evaporation temperature), without beinglimited to conductive materials.

Further, another aspect of the present invention is an evaporationdevice using the electrode cover.

In other words, an aspect of the present invention is an evaporationdevice including an evaporation source holder for holding an evaporationsource; and an electrode for heating the evaporation source; and anelectrode cover which covers at least a part of an exposed surface ofthe electrode is provided.

In addition, another aspect of the present invention is an evaporationdevice including an evaporation source holder for holding an evaporationsource; and an electrode for heating the evaporation source; and anelectrode cover which covers at least a face fronting the evaporationsource of an exposed surface of the electrode is provided.

Further, another aspect of the present invention is an evaporationdevice including an evaporation chamber; a holding portion for holdingan object to be treated; an evaporation source holder for holding anevaporation source; an electrode for heating the evaporation source; anelectrode cover; and a power supply, wherein the evaporation chamberincludes the holding portion in the upper part, and includes theevaporation source holder, the electrode, and the electrode cover in thelower part; the electrode cover covers at least a part of an exposedsurface of the electrode; the electrode and the power supply areelectrically connected; the evaporation source holder and the powersupply are electrically connected; and the evaporation source holder isheated by resistance heating so that a material held in the evaporationsource holder is deposited to the object to be treated which is heldabove the evaporation source holder. Note that the power supply may beprovided in the outside of the evaporation chamber.

In addition, another aspect of the present invention is an evaporationdevice including an evaporation chamber; a holding portion for holdingan object to be treated; an evaporation source holder for holding anevaporation source; an electrode for heating the evaporation source; anelectrode cover; and a power supply, wherein the evaporation chamberincludes the holding portion in the upper part, and includes theevaporation source holder, the electrode, and the electrode cover in thelower part; the electrode cover covers at least a face fronting anevaporation source side of an exposed surface of the electrode; theelectrode and the power supply are electrically connected; theevaporation source holder and the power supply are electricallyconnected; and the evaporation source holder is heated by resistanceheating so that a material held in the evaporation source holder isdeposited to the object to be treated which is held above theevaporation source holder.

In the above structures, the electrode cover preferably covers the wholeexposed surface of the electrode. Note that a connection portion ofparts of the electrode or a portion for connecting the electrode and thepower supply is not needed to be covered.

In addition, in the above structures, the electrode cover preferablycomprises a material having a high heat-resistance. Further, when anelectrode is constituted by plural parts and an electrode cover isprovided between the parts, the electrode cover preferably comprises aconductive material. Alternatively, when an electrode cover is notprovided between parts of the electrode, the electrode cover maycomprise a material having a higher temperature limit of heat-resistancethan a temperature at the time of evaporation (evaporation temperature),without being limited to conductive materials.

An electrode cover of the present invention is used, thereby preventingan evaporation material from being adhered to electrodes in anevaporation device.

Providing an electrode cover allows maintenance of an evaporation deviceto be easier, since the electrode cover can be detached in order toremove an evaporation material adhered to electrodes. Further, it leadsto increase in productivity of products which are manufactured with theevaporation device since the maintenance becomes easy and the processtime can be shortened.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIGS. 1A to 1D are views explaining an electrode cover and anevaporation device according to an aspect of the present invention;

FIGS. 2A to 2D are views explaining an electrode cover and anevaporation device according to an aspect of the present invention;

FIGS. 3A and 3C are views explaining an electrode cover and anevaporation device according to an aspect of the present invention;

FIGS. 4A and 4C are views explaining an electrode cover and anevaporation device according to an aspect of the present invention;

FIGS. 5A and 5C are views explaining an electrode cover and anevaporation device according to an aspect of the present invention;

FIGS. 6A and 6C are views explaining an electrode cover and anevaporation device according to an aspect of the present invention;

FIGS. 7A and 7C are views explaining an electrode cover and anevaporation device according to an aspect of the present invention;

FIGS. 8A to 8C are views each explaining an evaporation source holder;

FIGS. 9A to 9C are views each explaining an evaporation source holder;

FIGS. 10A and 10B are views explaining an evaporation device accordingto an aspect of the present invention; and

FIG. 11 is a view explaining a manufacturing apparatus according to anaspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, Embodiment Modes of the present invention will be describedwith reference to the drawings. Note that the present invention can becarried out in many different modes. It is easily understood by thoseskilled in the art that modes and details disclosed herein can bemodified in various ways without departing from the spirit and the scopeof the present invention. Therefore, it should be noted that the presentinvention should not be interpreted as being limited to the descriptionof the embodiment modes given below.

In addition, the light emitting device in this specification includesimage display devices, light emitting devices, and light sources(including a lighting system). Further, the light emitting deviceincludes all of the following modules: modules in which a connector suchas an FPC (Flexible Printed Circuit), a TAB (Tape Automated Bonding)tape, or a TCP (Tape Carrier Package) is attached to a panel; moduleshaving a TAB tape or a TCP provided with a printed wiring board at theend thereof; and modules having an IC (Integrated Circuit) directlymounted on a light emitting device by a COG (Chip On Glass) method.

Embodiment Mode 1

Embodiment Mode 1 will describe an evaporation device and an electrodecover according to the present invention.

FIGS. 1A to 1D show one mode of an evaporation device and an electrodecover according to the present invention. In FIG. 1A, the evaporationdevice includes a holding portion 103 for holding an object to betreated 102, a plate 104 on which an evaporation source holder is set,and the evaporation source holder 114 in an evaporation chamber 101. Anevaporation material held by the evaporation source holder 114 is heatedto form a film of the evaporation material on a surface of the object tobe treated held thereover. In FIG. 1A, a plate for preventing attachment107 is provided in order to prevent the evaporation material fromspreading in the whole evaporation chamber at the time of evaporation.The evaporation source holder 114 is electrically connected to a pair ofelectrodes, each of the electrodes comprising an upper part 111 a, amiddle part 111 b, and a lower part 111 c. And the middle part 111 b ofthe electrode and the lower part 111 c of the electrode are fixed on theplate 104 on which the evaporation source holder is set, with a screw112. The middle part 111 b of the electrode and the lower part 111 c ofthe electrode are electrically connected to each other with the screw112. The upper part 111 a of the electrode is fixed on the middle part111 b of the electrode with a screw 113. The evaporation source holderholding the evaporation material or an end portion of the evaporationsource holder including the evaporation material is interposed betweenthe upper part 111 a of the electrode and the middle part 111 b of theelectrode, so that the evaporation source holder 114 can be held. Inaddition, the electrodes and the evaporation source holder 114 can beelectrically connected. The lower part 111 c of the electrode which isfixed on the plate 104 on which the evaporation source holder is set canbe connected to a power supply 106.

When the plate 104 on which the evaporation source holder is setcomprises a conductive material, an insulating plate 105 a is providedbetween the plate 104 and the middle part 111 b of the electrode, and aninsulating plate 105 b is provided between the plate 104 and the lowerpart 111 c of the electrode. The insulating plates 105 a and 105 b canprevent a short circuit between the pair of electrodes via plate 104.

As the evaporation source holder, various types of evaporation sourceholders can be used. For example, a structure in which a boat 301 shownin FIG. 8A or a crucible shown in FIG. 8B is used and an evaporationmaterial stored in such a boat or such a crucible is heated by a heatingsource 303, or a structure in which a filament 304 comprising anevaporation material as shown in FIG. 8C is used, may be adopted. Inaddition, a structure in which an evaporation material is held by afilament may be adopted. The boat, crucible or filament may have variousshapes, for example, a boat which has an upper portion 401 and a lowerportion 402 and plural holes in the upper portion as shown 401 in FIG.9A, or a boat which has an upper portion 403 and a lower portion 404 andone hole in the upper portion 403 as shown in FIG. 9B can be used.Alternatively, a boat which has an upper portion 405, a middle portion406 and a lower portion 407 and one hole in the upper portion 405 andtwo holes in the middle portion 406 as shown in FIG. 9C, can be used.

The middle parts 111 b of the electrodes are covered by electrode covers121. FIG. 1B is a perspective view of the electrode cover 121 seen fromabove, and FIG. 1C is a perspective view of the electrode cover 121 seenfrom beneath. FIG. 1D is a perspective view of the middle part 111 b ofthe electrode seen from above. The sectioned face represented by X-Y inFIG. 1D corresponds to the cross section of the middle part 111 b of theelectrode in the left side of FIG. 1A. The middle part 111 b of theelectrode is electrically connected to the upper part 111 a of theelectrode with a screw 113, and the middle part 111 b of the electrodehas screw holes 141. In addition, the middle part 111 b of the electrodeshown in this embodiment mode includes a top face (a first face 131), aside face on the evaporation source side (a second face 132), a sideface opposite to the evaporation source side (a fourth face 134), otherside faces (a third face 133 and a fifth face 135), and a face frontingthe side of the plate 104 on which the evaporation source holder is set(a sixth face 136) as shown in FIG. 1D.

The electrode cover shown in FIG. 1A is provided to cover the otherfaces than a face of the middle part 111 b of the electrode fronting theplate 104 on which the evaporation source is set, and a portion forconnecting each part of the electrode. The sectioned face represented byX-Y in FIG. 1B corresponds to a cross section of the middle part 111 bof the electrode and the electrode cover 121 on the left side of FIG.1A. In FIGS. 1B and 1C, the electrode cover 121 is provided to cover theother faces than the face fronting the plate 104 (the sixth face 136)and the screw hole 141. In other words, the electrode cover 121 coversthe top face (the first face 131), the side face on the evaporationsource side (the second face 132), the side face opposite to theevaporation source side (the fourth face 134), and the other side faces(the third face 133 and the fifth face 135) of the middle part of theelectrode 111 b.

The electrode cover is preferably formed using a conductive material. Byusing the conductive material, the electrode can be electricallyconnected to the evaporation source holder 114. In addition, since theevaporation source holder reached high temperature during evaporation,the electrode cover is preferably formed using a high heat resistantmaterial. When an organic compound is evaporated, the electrode cover ispreferably formed using a material having a melting point of 300° C. orhigher. Further, when an inorganic compound whose evaporationtemperature is higher than that of an organic compound is evaporated,the electrode cover is preferably formed using a material having ahigher melting point, and the electrode cover is preferably formed usinga material having a melting point of 900° C. or higher. For example, ametal such as copper (Cu), gold (Au), silver (Ag), or platinum (Pt),which has a high melting point and excellent conductivity can be used.Alternatively, an alloy may be used.

The electrode cover 121 has a screw hole for fixing the upper part 111 aof the electrode on the upper side. Note that the screw 112 is formedusing a conductive material so that the middle part 111 b of theelectrode and the lower part 111 c of the electrode are electricallyconnected to each other.

FIGS. 2A to 2C show an evaporation device using an electrode coverhaving a different shape from that shown in FIGS. 1A to 1C. FIG. 2B is aperspective view of the electrode cover 122 seen from above and FIG. 2Cis a perspective view seen from beneath. FIG. 2D is a perspective viewof the middle part 111 b of the electrode. The sectioned facerepresented by X-Y in FIG. 2D corresponds to the cross section of themiddle part 111 b of the electrode in the left side of FIG. 2A. In FIGS.2A to 2D, the electrode cover 122 is provided to cover the other facesthan the face on the side opposite to the evaporation source side (thefourth face 134) and the face fronting the plate 104 (the sixth face136). In other words, the electrode cover 122 covers the top face (thefirst face 131), the side face on the evaporation source side (thesecond face 132), and the side faces (the third face 133 and the fifthface 135) of the middle part 111 b of the electrode.

In addition, FIGS. 3A and 3C show a structure in which an electrodecover 123 covers the other faces than the side faces (the third face 133and the fifth face 135) and the face fronting the plate 104 (the sixthface 136) of the middle part 111 b of the electrode, as another example.In other words, the electrode cover 123 covers the face on the sideopposite to the evaporation source side (the fourth face 134), the faceon the evaporation source side (the second face 132), and the face onthe upper part of the electrode side (the first face 131) of the middlepart 111 b of the electrode.

In addition, FIGS. 4A and 4C show a structure in which an electrodecover 124 covers the other faces than side faces (the third face 133 andthe fifth face 135), the face on the side opposite to the evaporationsource side (the fourth face 134), and the face fronting the plate 104(the sixth face 136) of the middle part 111 b of the electrode. In otherwords, the electrode cover 124 covers the face on the evaporation sourceside (the second face 132) and the face on the upper part of theelectrode side (the first face 131) of the middle part 111 b of theelectrode.

Moreover, FIGS. 5A and 5C show a structure in which the face on theevaporation source side (the second face 132) and the face on the upperpart of the electrode side (the first face 131) of the middle part 111 bof the electrode are covered, and a angled face for preventingattachment to side faces of the electrode (the third face 133 and thefifth face 135) are provided, as another example. Like the electrodecover 125 shown in FIGS. 5A and 5B, as long as attachment of theevaporation material to the electrodes can be prevented, the electrodecover is not needed to be in contact with the faces of the electrode.

Moreover, FIGS. 6A and 6C show an electrode cover 126 which covers onlyside faces (the second face 132, the third face 133, the fourth face 134and the fifth face 135) of the middle part 111 b of the electrode. Inother words, the electrode cover 126 covers the other faces than theface on the upper part of the electrode side (the first face 131) andthe face on the lower part of the electrode side (the sixth face 136).In the case of the electrode cover which covers only side faces of themiddle part 111 b of the electrode, no cover is on the lower and upperfaces of the middle electrode 111 b, and thus, the electrode iselectrically connected to an end portion of the evaporation sourceholder with no cover interposed therebetween. Thus, the electrode coveris not needed to have conductivity. Therefore, the electrode cover maybe formed using a high heat resistant material, for example, ceramic orthe like can be used. When an organic compound is evaporated, theelectrode cover is preferably formed using a material having anallowable temperature limit of 300° C. or higher. Further, when aninorganic compound whose evaporation temperature is higher than that ofan organic compound is evaporated, the electrode cover is preferablyformed using a material having a higher heat-resistance, and theelectrode cover is preferably formed using a material having anallowable temperature limit of 900° C. or higher.

In addition, FIGS. 7A and 7C show an electrode cover 127 which coversthe other faces than the face on the side opposite to the evaporationsource side (the fourth face 134), the face fronting the plate 104 (thesixth face 136), and the face on the upper part of the electrode side(the first face 131) of the middle part 111 b of the electrode. In otherwords, the electrode cover 127 covers the face on the evaporation sourceside (the second face 132) and the side faces (the third face 133 andthe fifth face 135) of the middle part 111 b of the electrode Theelectrode cover 127 shown in FIGS. 7A and 7B has no cover on the lowerand upper sides of the middle part of the electrode, similarly to theelectrode cover 126 shown in FIGS. 6A and 6B. Thus, the electrode cover127 is not needed to have conductivity.

As described above, since the electrode cover of the present inventionprevents attachment of the evaporation material to the electrode, theelectrode cover is preferably provided to cover at least a part of theexposed surface of the electrode. In particular, the electrode cover ispreferably formed to cover a face on the evaporation source side of theelectrode.

Note that the electrode cover can be used for not only the middle partof the electrode but also the upper part of the electrode. When theelectrode cover is used for the upper part of the electrode, adhesion ofthe evaporation material to the upper part of the electrode can beprevented. In addition, when a plurality of electrode covers are used,the number of cleaning electrodes can be decreased, and thus,maintenance work becomes simple and easy. Moreover, the electrode covermay be disposable. In other words, after an electrode cover is used, theelectrode cover may be disposed without cleaning. In that case, theelectrode cover is preferably formed using an inexpensive material. Inaddition, when the electrode cover is formed with a thin film, theelectrode cover can be formed at lower cost.

Note that there is no particular limitation on the shape of theelectrode. In addition, the electrode cover may be designedappropriately in order to prevent an evaporation material from beingadhered to the electrode, and there is no particular limitation on theshape of the electrode cover. For example, the electrode may have arectangular shape, a polygonal shape, or a columnar shape. When theelectrode is columnar, an electrode cover may be provided so as to covera face on the evaporation source side of the electrode. Preferably, theelectrode cover may be provided to cover more portions than half of theside face of the columnar electrode.

In addition, FIGS. 1A to 1D show that the upper part and the middle partof the electrode have the same cross sectional shape; however, the sizeand shape of each part of the electrode may be different. For example,the upper part of the electrode may be smaller than the middle part ofthe electrode. In that case, the electrode cover is preferably providedto cover a face between the middle part and the upper part of theelectrode.

Providing an electrode cover of the present invention allows maintenanceof an evaporation device to be easier, since the electrode cover can bedetached in order to remove an evaporation material adhered toelectrodes. Further, since maintenance becomes easy, the process timecan be shortened, which leads to increase in productivity of productswhich are manufactured with the evaporation device.

Embodiment Mode 2

Embodiment Mode 2 will describe an evaporation device having a pluralityof evaporation sources with reference to FIGS. 10A and 10B.

In FIGS. 10A and 10B, an evaporation device has a holding portion 203which holds an object to be treated 202, a plate 204 on which anevaporation source holder is set, and the evaporation source holder 214in an evaporation chamber 201. The evaporation source holder 214 iselectrically connected to a pair of electrodes. Of the electrodes, amiddle part 211 b of the electrode and a lower part 211 c of theelectrode are fixed on the plate 204 on which the evaporation sourceholder is set, with a screw 212. The middle part 211 b of the electrodeand the lower part 211 c of the electrode are electrically connected toeach other by the screw 112. The evaporation source holder 214 holdingan evaporation material or an end portion of the evaporation sourceholder comprising the evaporation material is interposed between anupper part 211 a of the electrode and the middle part 211 b of theelectrode, whereby the evaporation source holder 214 can be held. Inaddition, the electrodes and the evaporation source holder 214 can beelectrically connected. The lower part 211 c of the electrode which isfixed on the plate 204 on which the evaporation source holder is set canbe connected to a power supply 206.

When the plate 204 on which the evaporation source holder is setcomprises a conductive material, an insulating plate 205 a is providedbetween the plate 204 and the middle part 211 b of the electrode, and aninsulating plate 205 b is provided between the plate 204 and the lowerpart 211 c of the electrode. The insulating plates 205 a and 205 b canprevent a short-circuit between the pair of electrodes via plate 204.

In the evaporation device shown in FIGS. 10A and 10B, the plate 204 onwhich the evaporation source holders are set has a circular shape, and aplurality of evaporation source holders are arranged in a radialpattern. The circular shaped plate 204 has a rotation axis 207. Rotationaround the rotation axis 207 makes it possible to move the evaporationsources to a desired position and to connect them to the power supply206. The pair of electrodes connected to the evaporation source holdersmay have the same shape or may have different shapes. In addition, eachof the electrodes is provided with an electrode cover so that the sideface of the electrode fronting the evaporation source is covered.

When a plurality of evaporation sources are disposed in this manner inan evaporation device, the number of electrodes is large, and a lot oftime for maintenance work is required. However, the use of an electrodecover of the present invention can shorten the time for the maintenancework. Further, a plate on which a plurality of evaporation sourceholders are set weighs more, and thus there has been a difficulty inmaintenance work. However, the use of an electrode cover of the presentinvention can drastically reduce the maintenance work.

Embodiment Mode 3

Embodiment Mode 3 will describe one mode of a manufacturing apparatushaving a plurality of evaporation chambers and a method of manufacturinga light emitting device using the manufacturing apparatus with referenceto FIG. 11.

Specifically, a multi-chamber system manufacturing apparatus and amanufacturing method with the multi-chamber system will be described. Inthe manufacturing apparatus, a substrate 6111, which has been providedwith a thin film transistor, an anode (a first electrode), an insulatorcovering an end portion of the anode or the like in advance, isintroduced and a treatment such as deposition is continuously conducted;then, attached together with an opposing substrate which is introducedseparately from the substrate, a sealing treatment is conducted; andaccordingly, a panel is completed.

FIG. 11 shows a multi-chamber system manufacturing apparatus includingthe following: gates 6000 a to 6000 w, transfer chambers 6001 to 6005(each including a transfer robot 6112 for transferring a substrate), astock chamber 6011, delivery chambers 6012 to 6014, cassette chambers6020 a and 6020 b, a tray mounting stage 6021, a deposition chamber6022, a substrate heating chamber 6023, a substrate/mask stock chamber6024, a pretreatment chamber 6025, a substrate heating chamber 6026,evaporation chambers 6027Ha (EL layer: HTL, HIL), 6027Ra (EL layer: R),6027Ga (EL layer: G), 6027Ba (EL layer: B), and 6027Ea (EL layer: ETL,EIL), evaporation anterior chambers 6027Hb, 6027Rb, 6027Gb, 6027Bb, and6027Eb in which evaporation sources are set, evaporation chambers 6028and 6029, sputtering chambers 6030 and 6031, a N₂ displacement chamber(for an opposing glass substrate) 6032, a glove box 6033, a preparationchamber 6034, a substrate/opposing-substrate stock chamber 6035, asealing chamber 6036, and a chamber for taking out 6037.

A cassette storing a substrate is put in the cassette chamber 6020 a orthe cassette chamber 6020 b.

Metal masks used in a total of 10 chambers of the pretreatment chamber6025, the evaporation chambers 6027Ha, 6027Ra, 6027Ba, 6027Ga, and6027Ea, the evaporation chambers 6028 and 6029, and the sputteringchambers 6030 and 6031 are set in the substrate/mask stock chamber 6024.

A heater (a sheath heater or the like) provided in the pretreatmentchamber 6025 or the substrate heating chamber 6026 can heat a substrate.In order to completely remove water and other gases contained in thesubstrate, annealing for degassing is performed in a vacuum (less thanor equal to 5×10⁻³ torr (0.665 Pa), preferably 10⁻⁴ to 10⁻⁶ Pa). Inparticular, when an organic resin film is used as a material of aninterlayer insulating film or a partition wall, certain organic resinmaterials may absorb water easily and may further cause degassing.Therefore, it is effective to perform vacuum heating before forming anEL layer, in which heating is performed at 100° C. to 250° C.,preferably at 150° C. to 200° C., for 30 minutes or more and thennatural-cooling is performed for 30 minutes to remove absorbed water.

Subsequently, after the vacuum heating, the substrate is transferredfrom the transfer chamber 6002 to the evaporation chamber 6027Ha, wherevacuum evaporation is performed to form a hole injecting layer and/or ahole transporting layer. Then, the substrate is transferred from thetransfer chamber 6002 to the transfer chamber 6003 which is constantlymaintained under a vacuum through the delivery chamber 6012, which isconstantly maintained under a vacuum.

Then, the substrate is transferred to the evaporation chambers 6027Ra,6027Ga, 6027Ba, and 6027Ea connected to the transfer chamber 6003appropriately, where each layer of a red light emitting layer, a greenlight emitting layer, a blue light emitting layer, and an electrontransporting layer, an electron injecting layer or the like, is formedusing a vacuum evaporation method. Here, the evaporation chambers6027Ha, 6027Ra, 6027Ga, 6027Ba, and 6027Ea are described below.

Each of the evaporation chambers 6027Ha, 6027Ra, 6027Ga, 6027Ba, and6027Ea is provided with an evaporation source holder on which aplurality of evaporations sources can be set, and electrodes.Multi-source co-evaporation can also be easily performed. In addition,each evaporation source is provided with an evaporation source shutterto control whether to actually evaporate a material by opening andclosing of the shutter.

It is preferable to use the following manufacturing system whenevaporation materials are set in the evaporation chambers. In otherwords, it is preferable to use containers (typically, such as a crucibleand a boat) in which the evaporation material is stored in advance by amaterial manufacturer for deposition. It is also preferable to providethe evaporation material without being exposed to the atmosphere, and itis preferable to put the crucible into the deposition chamber as thecrucible is sealed in a second container during transportation from thematerial manufacturer. It is desirable that the evaporation anteriorchambers 6027Hb, 6027Rb, 6027Gb, 6027Bb, and 6027Eb which have vacuumexhaust means and are connected to the evaporation chambers 6027Ha,6027Ra, 6027Ga, 6027Ba, and 6027Ea be maintained under a vacuum or aninert gas atmosphere, in which the crucible is taken out from the secondcontainer and set in the evaporation source holder of the evaporationchamber. Thus, the evaporation material can be set in the evaporationsource without exposing each of the evaporation chambers 6027Ha, 6027Ra,6027Ga, 6027Ba, and 6027Ea to the atmosphere, and further the crucibleand the evaporation material contained in the crucible can be maintainedin a clean condition until immediately before evaporation.

In addition, in the evaporation chamber, the electrode is covered withan electrode cover of the present invention shown in Embodiment Mode 1to prevent adhesion of the evaporation material to the electrodes.Therefore, in a large manufacturing apparatus as shown in thisembodiment mode, maintenance work can be reduced and productivity isimproved.

Appropriate selection of evaporation materials to be used in theevaporation chambers 6027Ha, 6027Ra, 6027Ga, 6027Ba, and 6027Ea makes itpossible to form a light emitting device that exhibits single-color (forexample, white) or full-color (red, green, and blue) light emission inthe whole light emitting device.

After the EL layers are formed appropriately in the above steps, thesubstrate is transferred from the transfer chamber 6003 to the transferchamber 6004, which is constantly maintained in a vacuum, through thedelivery chamber 6013 which is constantly maintained in a vacuum.

Subsequently, a cathode (a second electrode) is formed. In a case inwhich the cathode is formed as a reflective electrode, an element whichbelongs to the first group or the second group of the periodical table,that is, an alkaline metal such as Li (lithium) or Cs (cesium), analkaline earth metal such as Mg (magnesium), Ca (calcium), or Sr(strontium), an alloy thereof (MgAg and AlLi), an rare earth metal suchas Eu (europium) or Yb (ytterbium), or an alloy thereof can be used. Forexample, Al (aluminum) may be formed by a vacuum evaporation methodusing resistance heating in the evaporation chamber 6028 or 6029, oralternatively can be formed by a sputtering method in the sputteringchamber 6030 or 6031.

Lastly, a calcium fluoride (abbreviation: CaF₂) or zinc oxide(abbreviation: ZnO) transparent protective film is formed in theevaporation chamber 6028 or 6029.

In addition, in the evaporation chamber, the electrode is covered withan electrode cover of the present invention shown in Embodiment Mode 1to prevent adhesion of the evaporation material to the electrodes.Therefore, in a large manufacturing apparatus as shown in thisembodiment mode, maintenance work can be reduced and productivity isimproved.

The light emitting element with a multilayer structure is formed throughthe above steps.

Subsequently, the substrate over which a light emitting element isformed is sealed in the sealing chamber 6036 and thus, a panel iscompleted. The thus completed panel is transferred to the chamber fortaking out 6037 through the transfer chamber 6005 and is taken out.

The use of the manufacturing apparatus in the above procedure makes itpossible to manufacture a light emitting device.

The manufacturing apparatus shown in this embodiment mode is a largemanufacturing apparatus having a plurality of evaporation chambers. Inthe case of such a large manufacturing apparatus, maintenance work ismuch harder than that of a small manufacturing apparatus. However, theuse of an electrode cover of the present invention can drasticallyreduce the maintenance work. In addition, the time for the maintenancework is shortened, and therefore productivity is improved.

This application is based on Japanese Patent Application serial no.2006-126794 filed in Japan Patent Office on Apr. 28, 2006, the entirecontents of which are hereby incorporated by reference.

What is claimed is:
 1. An electrode cover comprising: a first portionconfigured to cover a first side surface of a first electrode, the firstside surface facing to an evaporation source holder which is configuredto hold an evaporation material; a second portion configured to cover anupper portion of the first electrode, to hold the evaporation sourceholder by sandwiching the evaporation source holder with a secondelectrode located over the first electrode, and to electrically connectthe evaporation source holder to the first electrode; and a thirdportion configured to be apart from the first electrode so that thefirst portion is arranged closer to the evaporation material than thethird portion when the electrode cover is attached to the firstelectrode, wherein the second portion comprises a hole to bolt the firstportion to the first electrode, and wherein the third portion is a faceinclined with respect to a second side surface of the first electrode,wherein the second side surface is substantially perpendicular to thefirst side surface.
 2. The electrode cover according to claim 1, whereinthe electrode cover comprises a material having a melting point of 300°C. or higher.
 3. The electrode cover according to claim 1, wherein thefirst portion, the second portion, and the third portion are physicallyconnected with one another.
 4. The electrode cover according to claim 1,wherein the electrode cover comprises a material selected from the groupconsisting of copper, gold, silver, and platinum.
 5. An evaporationdevice comprising: an evaporation chamber comprising: a plate; a pair offirst electrodes connected to the plate, wherein each of the firstelectrodes is capable of holding an evaporation source holder, which isconfigured to hold an evaporation material, by sandwiching thereof witha second electrode located over each of the first electrodes; and anelectrode cover comprising a first portion, a second portion, and athird portion, wherein the first portion is configured to cover a firstside surface of at least one of the first electrodes, the second portionis configured to cover a top surface of at least one of the firstelectrodes, and the third portion is configured to be apart from atleast one of the first electrodes so that the first portion is arrangedcloser to the evaporation material than the third portion when theelectrode cover is attached to at least one of the first electrodes,wherein the first side surface faces to the evaporation source holder,wherein each of the first electrodes and the evaporation source holderare electrically connected to each other through the second portion,wherein the second portion comprises a hole to bolt the first portion toat least one of the first electrodes, and wherein the third portion is aface inclined with respect to a second side surface of at least one ofthe first electrodes, wherein the second side surface is substantiallyperpendicular to the first side surface.
 6. The electrode coveraccording to claim 1, wherein the electrode cover is capable of beingdetached from the first electrode and the evaporation source holder. 7.The electrode cover according to claim 1, further comprising a fourthportion configured to be apart from the first electrode when theelectrode cover is attached to the first electrode.
 8. An evaporationdevice comprising: a first electrode; an electrode cover comprising afirst portion, a second portion, and a third portion; and a secondelectrode over the first electrode, wherein the first portion isconfigured to cover a first side surface of the first electrode, whereinthe first side surface faces to an evaporation source holder which isconfigured to hold an evaporation material, wherein the second portionis configured to cover an upper portion of the second electrode, to holdthe evaporation source holder by sandwiching the evaporation sourceholder with the second electrode, and to electrically connect theevaporation source holder to the first electrode, wherein the thirdportion is configured to be apart from the first electrode so that thefirst portion is arranged closer to the evaporation material than thethird portion when the electrode cover is attached to the firstelectrode, wherein the second portion comprises a hole to bolt the firstportion to the first electrode, and wherein the third portion is a faceinclined with respect to a second side surface of the first electrode,wherein the second side surface is substantially perpendicular to thefirst side surface.
 9. The evaporation device according to claim 8,wherein the first portion, the second portion, and the third portion arephysically connected with one another.
 10. The evaporation deviceaccording to claim 8, wherein the electrode cover comprises a materialhaving a melting point of 900° C. or higher.
 11. The evaporation deviceaccording to claim 8, wherein the electrode cover comprises a materialselected from the group consisting of copper, gold, silver, andplatinum.
 12. The evaporation device according to claim 8, wherein theelectrode cover is capable of being detached from the first electrodeand the evaporation source holder.
 13. The evaporation device accordingto claim 8, wherein the electrode cover further comprises a fourthportion configured to be apart from the first electrode when theelectrode cover is attached to the first electrode.
 14. An evaporationdevice comprising: an evaporation chamber comprising: a holding portionfor holding an object to be treated, in an upper part of the evaporationchamber; a first electrode which is capable of holding an evaporationsource holder by sandwiching the evaporation source holder with a secondelectrode located over the first electrode, wherein the evaporationsource holder is configured to hold an evaporation material; anelectrode cover comprising a first portion, a second portion, and athird portion, wherein the first portion is configured to cover a firstside surface of the first electrode, the second portion is configured tocover a top surface of the first electrode, and the third portion isconfigured to be apart from the first electrode so that the firstportion is arranged closer to the evaporation material than the thirdportion when the electrode cover is attached to the first electrode; andwherein the first side surface faces to the evaporation source holder, apower supply being connected to the first electrode, wherein theevaporation source holder is arranged to be heated by resistance heatingso that a material held in the evaporation source holder is deposited tothe object to be treated, wherein the first electrode and theevaporation source holder are electrically connected to each otherthrough the second portion, wherein the second portion comprises a holeto bolt the first portion to the first electrode, and wherein the thirdportion is a face inclined with respect to a second side surface of thefirst electrode, wherein the second side surface is substantiallyperpendicular to the first side surface.
 15. The evaporation deviceaccording to claim 14, wherein the electrode cover comprises a materialhaving a melting point of 300° C. or higher.
 16. The evaporation deviceaccording to claim 14, wherein the first portion, the second portion,and the third portion are physically connected with one another.
 17. Theevaporation device according to claim 14, wherein the electrode covercomprises a material selected from the group consisting of copper, gold,silver, and platinum.
 18. The evaporation device according to claim 14,wherein the electrode cover is capable of being detached from the firstelectrode and the evaporation source holder.
 19. The evaporation deviceaccording to claim 14, wherein the electrode cover further comprises afourth portion configured to be apart from the first electrode when theelectrode cover is attached to the first electrode.
 20. The evaporationdevice according to claim 5, wherein the electrode cover comprises amaterial selected from the group consisting of copper, gold, silver, andplatinum.
 21. The evaporation device according to claim 5, wherein theevaporation source holder is capable of attaching to the firstelectrodes by a screw using the hole of the second portion.
 22. Theevaporation device according to claim 5, further comprising a secondpair of first electrodes and a second evaporation source holder forholding a second evaporation source.
 23. The evaporation deviceaccording to claim 5, wherein the plate is capable of rotating around arotation axis in the evaporation chamber.
 24. The evaporation deviceaccording to claim 5, wherein the electrode cover comprises a materialhaving a melting point of 300° C. or higher.
 25. The evaporation deviceaccording to claim 5, wherein the first portion, the second portion, andthe third portion are physically connected with one another.
 26. Theevaporation device according to claim 5, wherein the electrode cover iscapable of being detached from at least one of the first electrodes andthe evaporation source holder.
 27. The evaporation device according toclaim 5, wherein the electrode cover further comprises a fourth portionconfigured to be apart from at least one of the first electrodes whenthe electrode cover is attached to at least one of the first electrodes.